Prostate cancer develops in the prostate and is typically slow growing; however, some prostate cancers are aggressive. Prostate cancer cells are typically androgen/testosterone/DHT dependent and may metastasize from the prostate to other parts of the body, particularly the bones and lymph nodes. Treatment options for prostate cancer that remains within the prostate include watchful waiting/active surveillance, external beam radiation therapy, brachytherapy, cryosurgery, high-intensity focused ultrasound (HIFU), and surgery. Hormonal therapy and chemotherapy are often reserved for disease that has spread beyond the prostate. However, there are exceptions in that radiation therapy may be used for some advanced tumors, and hormonal therapy may be used for some early stage tumors.
After one to three years of hormonal therapy, it is common that prostate cancer cells resume growth despite the androgen/testosterone/DHT blockade. Previously referred to as “hormone-refractory prostate cancer” or “androgen-independent prostate cancer,” the term castration-resistant prostate cancer (CRPC) is now commonly used. Chemotherapeutic agents and immunotherapy have been shown to prolong survival after CRPC but the survival benefit is limited. Despite the efforts of many, the need for more cancer treatments, in particular prostate cancer treatments, is manifest.